All posts tagged: ancient DNA

Plague was killing hunter-gatherers 5,500 years ago, long before cities

Plague was killing hunter-gatherers 5,500 years ago, long before cities

Published by Jenni Sidey

Plague did not wait for medieval cities, crowded streets, or shipborne rats to become deadly. More than 5,500 years ago, the disease was already killing people in small hunter-gatherer communities near Lake Baikal in East Siberia, according to a new study in Nature. The evidence comes from ancient DNA preserved in teeth, where researchers found the bacterium Yersinia pestis in nearly 40 percent of the individuals tested from four cemeteries. That level of detection startled the research team. It also helped solve a puzzle that had troubled archaeologists for decades: why so many children and young teenagers were buried at two of the largest sites, and why so many of those burials appeared to have happened within a narrow span of time. “Whether the earliest forms of plague were mild or virulent has been a matter of debate, but our findings demonstrate that these ancient strains were already highly lethal,” says senior author Eske Willerslev, Professor at the University of Copenhagen and the University of Cambridge. Overview of the spatiotemporal distribution of ancient humans and …

Ancient squirrel droppings reveal 700,000 years of lost ecosystems

Ancient squirrel droppings reveal 700,000 years of lost ecosystems

Published by Jenni Sidey

Frozen deep beneath the Yukon’s permafrost, small pellets left behind by ancient ground squirrels have preserved a record of life that stretches back hundreds of thousands of years. What appears unremarkable at first glance has now become one of the richest sources of ancient DNA ever studied. In new research, scientists report that these fossilized droppings contain genetic material from entire ecosystems. The findings offer a rare window into a world that no longer exists, capturing plants, animals, and microbes from as far back as 700,000 years ago. A Time Capsule Frozen In Ice The Arctic ground squirrel, known scientifically as Urocitellus parryii, plays a central role in this discovery. These animals dig burrows into the soil and hibernate for months at a time. During this period, they store food, gather materials, and leave behind waste. Coprolites processed for ancient environmental DNA with their midden locations. (CREDIT: Nature Communications) Over thousands of years, these burrows remained frozen and undisturbed. The result is a natural archive of biological material, sealed away from decay. “The research shows …

DNA evidence points to a massive stone age population collapse

DNA evidence points to a massive stone age population collapse

Published by Jenni Sidey

A stone tomb near Paris held generations of dead, but the people buried there did not all belong to the same world. That is the striking picture emerging from new genetic work on 132 individuals buried at Bury, a large Neolithic megalithic site about 50 kilometers north of Paris. The tomb was used in two separate phases, first around 3200 to 3100 BC. Then it was used again across much of the third millennium BC until about 2450 BC. Between those periods, something appears to have gone badly wrong. The break is not subtle. The people buried in the earlier phase were not closely related to the later group. Instead, the DNA points to a major population turnover. This fits into a broader pattern of demographic upheaval that seems to have affected much of northwestern Europe at the end of the fourth millennium BC. “We see a clear genetic break between the two periods,” said Frederik Valeur Seersholm, an assistant professor at the Globe Institute at the University of Copenhagen and one of the study’s …

Natural selection is accelerating, massive DNA study finds

Natural selection is accelerating, massive DNA study finds

Published by Jenni Sidey

For years, the story of recent human evolution looked relatively quiet. Scientists studying ancient human DNA had found only a few dozen clear cases where natural selection appeared to strongly favor one version of a gene over another. As a result, it made it seem as though the most forceful kind of selection had played only a limited role after modern humans spread out of Africa. In addition, they formed distinct populations around the world. A new analysis upends that picture. Drawing on DNA from nearly 16,000 ancient people across West Eurasia, researchers found that directional selection, the kind that pushes certain genetic variants to rise or fall in frequency because they help or hurt survival and reproduction, has been far more common than once believed. Moreover, the team identified hundreds of such cases over the past 10,000 years. Selection appears to speed up after the rise of farming. The work, led by researchers at Harvard, was published in Nature. David Reich (left), Ali Akbari (right), and colleagues studied thousands of ancient genomes from West …

Major scientific breakthrough reveals even cavemen had pet dogs | World | News

Major scientific breakthrough reveals even cavemen had pet dogs | World | News

Published by Sam Flores

14,300-year-old dog jawbone from Gough’s Cave, UK (Image: The Trustees of the Natural History Museum) Dogs were living alongside humans in Europe and Turkey around 16,000 years ago, a new study published reveals. Researchers analysed ancient DNA from archaeological sites, including Gough’s Cave in the UK and Pınarbaşı in Turkey, dating back to approximately 16,000-14,000 years ago, a time when all humans were hunter-gatherers and agriculture had not yet emerged. The findings have confirmed that these were some of the earliest known domestic dogs. While it has long been known that dogs descended from grey wolves, determining when their domestication occurred has been difficult. Early dog skeletons often resembled wolves, and previous studies relied on short DNA sequences or skeletal measurements, making early identification uncertain. However, in this study, scientists from 17 institutions recovered whole genomes from specimens older than 10,000 years. Comparing them with over 1,000 ancient and modern dogs and wolves confirmed the bones were dogs, pushing back the earliest direct evidence by more than 5,000 years. READ MORE: Scientific breakthrough as major …

Evidence of an Ice Age forest emerges from the North Sea floor

Evidence of an Ice Age forest emerges from the North Sea floor

Published by Jenni Sidey

The North Sea is home to the remains of a vast land that has been lost to time and is referred to as Doggerland, the area of land that connected Great Britain to continental Europe following the last glacial (ice) age. Recent genetic research shows that this submerged area of land supported trees many thousands of years earlier than previously believed. Research shows trees existed in Doggerland 16,000 or more years ago, long before there were forests in Great Britain. This study was conducted by researchers at the University of Warwick through a large sampling of ancient DNA (aDNA) from sedimentary deposits. The work was published in the journal Proceedings of the National Academy of Sciences. The findings of this study indicate that Doggerland was not only a migration route between the continents but likely provided a habitat for the flora and fauna of the region during colder climatic periods. Additionally, this area would have provided a welcoming habitat for the early human populations living in this part of the world. Doggerland landscape 18,000, 10,000 …

Neanderthal males preferred human females, genetic study finds

Neanderthal males preferred human females, genetic study finds

Published by Jenni Sidey

Thin stretches of the human X chromosome look oddly empty when you scan for Neanderthal DNA. Geneticists even have a name for the gaps: “Neanderthal deserts.” They sit there like blank tape in an otherwise crowded recording. For years, the standard story went like this: Neanderthal DNA landed in our ancestors’ genomes. However, some of it was harmful, especially on the X chromosome. Natural selection, the thinking said, gradually stripped those “toxic” variants away. A new analysis from Sarah Tishkoff’s lab at the University of Pennsylvania argues that the emptiness may say more about who paired with whom than which genes were dangerous. In Science, the team reports a mirror-image pattern inside Neanderthal genomes. Neanderthals carried unusually high levels of modern human DNA on their X chromosomes compared with the rest of their genome. That reversal, they say, makes simple “toxicity” a much harder explanation to defend. The deserts and the old assumption “Along our X chromosomes, we have these missing swaths of Neanderthal DNA we call ‘Neanderthal deserts,’” says Alexander Platt, a senior research …

Iron Age mass grave reveals targeted violence against women and children

Iron Age mass grave reveals targeted violence against women and children

Published by Jenni Sidey

Bones lay tightly packed inside what had once been a semi-subterranean house, along with bronze ornaments, pottery vessels, and the butchered remains of animals. The scene was not chaotic. It was arranged. Archaeologists studying the Early Iron Age site of Gomolava in northern Serbia now say the burial represents one of the largest prehistoric mass killings in Europe, and one that appears to have deliberately targeted women and children. Their findings, published in Nature Human Behaviour, challenge long-held assumptions about how violence operated in prehistoric societies. The grave contained the remains of at least 77 people buried around 2,800 years ago. Most were female, and more than half were children. “When we encounter mass graves from prehistory with this kind of demographic, we might expect they were families from a village that was attacked,” said co-lead Associate Professor Barry Molloy of University College Dublin’s School of Archaeology. “Gomolava genuinely took us by surprise when our genetic analysis showed the majority of people studied were not only unrelated, not even their great–great-grandparents were.” Map showing the …